AJAX response to update a component doesn't include the updated component's root tag

Details

Description

Currently a component scheduled to be updated in an ajax request via @EventListener gets only its body replaced.
This leads to somewhat counterintuitive behaviour.
E.g.: Firefox accepts the xml-snippets with multiple root elements, that can result from this, IE 6 does not.

Since it's easy to work around that, it could also fixed by documenting it if it's hard to do otherwise.